What is filtration?

The movement of substances out of the blood into the filtrate. Glomerulus into the PCT.

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What is reabsorption?

The return of substances from filtrate now present in the tubular fluid back into the blood.

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What is secretion?

The movement of substances out of peritubular blood via kidney tubule cells in tubular fluid.

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What is the vasa recta?

Capillaries located around the LoH; absorb interstitial fluid without excessive removal of interstitial solute.

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What is the renal corpuscle?

Glomerulus and Bowman's space

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What is the kidney's release of renin stimulated by (RAAS stimulation)?

Decreased BPDecreased fluid volumeIncreased B1-Sympathetic

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What is the RAAS inhibited by?

Increased BPIncreased fluid volume Decreased B1-Sympathetic ANP

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What are the steps of the RAAS?

In response to decreased BP or volume renin is released by the kidneys. Renin acts on the liver which release Angiotensinogen that is cleaved by the renin resulting in Angiotensin I which is converted via the lungs by ACE to Angiotensin II which stimulates the adrenal cortex to release Aldosterone. Aldosterone acts on the distal portion of the nephron to increase Na K ATP pumps to increased the reabsorption of Na and H2O=increased blood volume and BP

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In addition to stimulated the release of Aldosterone what does Angiotensin II do?

Causes vasoconstriction

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How are the capillaries of the glomerulus different from other capillary networks in the body?

Glomerular capillaries branch from and drain into arterioles

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Why is there no oncotic pressure in Bowman's space?

This area should be protein free which is indicative of decreased oncotic pressure

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Why is the NFP in the efferent arteriole=0?

No filtration happens here.

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What is the purpose of the podocytes?

Surround the fenestrated epithelium and are negatively charged, so they provide a barrier to movement of negatively charged ions

How does each nephron regulate its own GFR?

Tubuloglomerular feedback

What is the regulatory structure that controls tubuloglomerular feedback?

What does the macula densa do?

Located near the end of the ascending LoH in the DCT. Senses changes in the amount of NaCl. Increased NaCl inhibits renin release and a decreased load promotes renin release (decreased amount of tubular fluid moving by)

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What do the juxtaglomerular cells do?

Surround afferent arteriole. Produce and release renin

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How is bicarbonate reabsorbed?

Bicarb is converted to CO2 and H20 via carbonic anhydrase in the PCT. Carbonic anhydrase is then used to the catalyze the reverse reaction creating H and bicarb; bicarb is reabsorbed back into the blood via the Na HCO3 transporter and H is excreted in the urine

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What does decreased reabsorption cause?

Dilution of urine and overall increase in fluid volume

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How is sympathetic nerve activity related to the 'fight or flight' response in the kidneys?

Diverts blood from kidneys and GI tract. Increases fluid reabsorption to shut of ability to make urine (Na and H2O reabsorbed)

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What affect does in an increase in pressure sensed by baroreceptors in the afferent arteriole cause?

Genetically transmitted. Autosomal recessive (often lethal and do not make it to reproductive age= less common)Autosomal dominate (Chromosome 16 PKD1 most common and Chromosome 4 PKD2)

What is cystic kidney disease?

Decreased cilia formation of the epithelial cells in the nephron that should detect pressure and solute content passing through and stimulate Ca and cAMP. Decreased intracellular Ca and excessive intracellular cAMP causes reduction of normally function kidney tissue and development of cysts.

Proteinuria leads to hypoalbuminemia which stimulates the liver to increased fat production (hyperlipidemia) and clotting factor production (hypercoagulability)

How can proteinuria cause generalized edema?

What is minimal change disease or MCD?

-Lipoid nephrosis -Initiated by allergic or immune condition causing decreased GFR- Fusion of the glolmerular podocytes and decreased production of anions of the basement membrane =decreased barrier)-Occurs in children -Sudden onset of edema, nephrotic levels of proteinuria, and hypoalbuminemia

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What is acute glomerulonephritis?

Acute inflammation of the glomerulus. Related to antibody deposition leading to inflammation which results in lysosomal degradation of the basement membrane.GFR may fall d/t contraction of mesangial cells